Plate-holder for photographic cameras



NM0de1 W. H. WALKER.

PLATE HOLDER POR PHOTOGRAPHIG CAMERAS. No. 254,180. Patented Feb. 28,1882.

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UNITED STATES PATENT OFFICE.

WILLIAM H. VALKIGR, OF ROCHESTER, NEW YORK.

PLATE-HOLDER FOR PHOTOGRAPHIC CAMERAS.

SPECIFICATION forming part of Letters Patent No. 254,180, dated February 28, 1882,

Application filed April 9, 1881. (No model.)

To all whom it may concern:

Be itknown thatLWILLIAM HALL WALKER, of the city of Rochester, in the county ot Monroe and the State of New York, have invented certain Improvements in Plate Holders for Photographic Cameras, ot' which the following is a specification, reference being had to the annexed drawings.

The primary object ot' my invention is to produce a holder wherein dry plates may be carried with safety, and which shall be free from the danger-(which now exists in all holders known in the art) of the entrance of light through thejoints and angles, and to this end it consists lin constructing the frame of the holder of plastic material by means of a mold, whereby I am enabled to produce a. holder Without seams or joints, and which must consequently remain permanently tight.

Hitherto plate-holders have been constructed of various materials, generally of wood,

built up in a number of pieces, glued or otherwise secured together. In practice it has been found that in course ot' time the strains and shocks to which they are subjected, the shrinkage of the wood, and other causes open the joints or seams in such manner as to admitlig'ht to the interior. In the use of dry plates, which frequently remain in the holders for a great length of time, and which are commonly made of a very high degree of sensitive'ness, this leakage of the light in the ordinary holders has been found a source of constant and serious trouble, resultingv in a constant and extensive loss of plates. Owing to the fact that it is impossible to determine in advance whether a plate has been ruined by theadmission of light, the operations of the photographer have been rendered extremely hazardous and uncertain, it being frequentlyfound after an exposure of the plates in the instrument that they had been previously destroyed by the leakage of thc light. By means of my improvement these difficulties are entirely obviated. The photographer is enabled to preserve the plates in their sensitive condition for an indefinite length of time, and to make the :exposures with the assurance that the plate is in proper condition, thus avoiding the usual practice and the attendant expense of exposing' additional plates as a precautionary measure.

My improvements in plate-holders for photographic cameras are represented in theaccompanying drawings, in which- Figure 1 is a plan view ofmyimproved plateholder. Fig. 2 is an end elevation ofthe same. Fig. 3 is a perspective view ot' a die or mold with collapsible center used in forming my improved plate-holder. Fig. et is a central longitudinal section through the same. Fig. 5 is a side view of my improved plate-holder. Fig. 6 is a section through the end bar of my improved plate-holder on the line :c x of Fig. l. Fig. 7 is a longitudinal section of the same on the line y y ot' Fig. 1. Fig. 8 is a horizontal section ot' the same on the line .e z of Fig. 5. Fig. 9 is a perspective view of one-half of the mold in which my improved plate-holder is formed. Fig. l() is a section through the end bar of my improved plate-holder on the line 00 a: of Fig. l, showing the arrangement of the shutters for excluding the light when the slides are withdrawn. Figs. l1 and 12 are respectively side and end views ot the springs to which the light-shutters are attached. Fig. 13 is a perspective view of my improved plateholder as it would appear when cut in two on the line a" .12 ofFig. 1, showing the parts to the right hand of that line. Fig. 14 is a partial section of the mold with a collapsible center for the manufacture of my improved plateholder, on an enlarged scale.

My improved plate-holder is represented in the accompanying drawings, in which A is the frame, B,theslide; C,thewallorseptum which separates the plates, and F the recess in which the light-excluding shutters o o are supported on the spindle h.

The external appearance of my improved plate-holder resembles the wooden ones heretofore in use, except that the edges may be grooved or channeled, as shown at e in the drawings, t'oreconomy of material and to secure lightness.

My improved plate-holder may be made of any desired form or size and adapted to hold either one or two plates. It may be used in connection with any ordinary camera, and for this purpose it is provided with the usual pro- ICO jecting ledge or shoulder (shown at d in the various drawings) for the purpose of preventing light from entering the camera between it and the holder.

In the manufacture of my improved plateholder I form the frame A by molding it in a mold or die out of any suitable plastic material.

I have represented a mold suitable for making the frame in Fig. 9, in which the sides and ends of the frames are molded in the grooves g g, while the septum or wall C, which separates the plates in a double holder, is formed in the recess n. The two halves of the die E E are secured in the proper relative positions by the dowels i t', or by screws, clamps, 0r other suitable devices, during the process of drying or hardening the plastic material.

The grooves l l', Figs. 6 and 10, for the receptiou of the slides B are worked through the end bar of the frame by a thin circular saw, the ends ofthe grooves being worked out by a straight-edged saw. l

The recess F, which contains the light-shutters o o, may be made by boring into the end bar of the frame. The shutters o o are secured in the recess in the proper position to close the grooves Z l when the slides B-are withdrawn by being attached to the springs m m on the rod or spindle h, which passes lengthwise through the recess, being provided with a cap or socket, D, to close the open end of the recess. The recess may also be formed by molding it in the end bar in a mold with removable sides havin g a rod or bar projecting inward therefrom, the advantage of the latter mode of manufacture being that the recess may be of any desired form-triangular or oblong-as may be desired. Two recesses may also be employed, one to receive each shutter. The cap D may be secured in place by driving it in tight or by inserting a pin or screw from the outside of the frame. One of the principal advantages of this mode of inserting the shutters into the frame is that it permits of the easy removal of the shutters in case repairs are needed by them or their springs. The spindle h passes into an opening at the bottom of the recess F, in order that it may be held in place thereby. rlhe recess F may be made to extend entirely through the frame, being closed at each end by caps secured in place in any convenient manner.

The grooves r o s s', Fig. 13, for the reception of the sensitive plates and the slides B, respectively, may be formed in the inner man gins of the frame by a small circular saw of the proper width and arranged to cut to the proper depth,the round corners of the grooves as left by the saw being worked out squarely by a chisel or other appropriate tool or the grooves may be cut deep enough to prevent the round corners from interfering with the introduction of the plates, while the corners of the slides may be rounded. Another way of holding the plates in place consists in inserting pins in two inner and opposite sides'of the frame. It will be observed that the grooves are placed on two opposite sides of the frame, the intention being to introduce the plate by compressing a spring in one ot the grooves by pressing one edge ot' the plate against it, while the other edge is placed in position to enter the opposite groove, being forced into it by the spring.

My improved plate-holder may be molded from any suitable plastic material. It maybe made ot' hard rubber, celluloid, papier-mache, wood pulp, or sawdust cemented together by shellac, or any other preferred substance capable of being formed in a mold.

Instead of being worked out by a saw or other'mechanism, the grooves for the plates and slides may be molded by the mold having a collapsible or movable center, (represented in Figs. 3, 4, and 14.) This mold consists of two outer plates, E and. E', of a form and size to shape the outer flat sides of a frame. The edges of the frame are formed by the bars H BI', to which the side plates, E and Ef, are removably attached in any convenient manner. Each side plate is provided with a collapsible center, between which the wall or septum Gis molded. The collapsible center consists of three plates, o p z, the two latter projecting outward so as to form the grooves o r s s', and, if preferred, the grooves Z l in the end bar for the reception of the slide B. The plates fv zp are formed in sections in any preferred manner, so that, the central section being takenout, the projecting edges of the plates may be withdrawn from the grooves andthe center removed from the molded frames. A convenient way of accomplishing this is to divide the plates into the sections at p, as shown in Fig. 3. These sections are fastened from the outside ofthe plates E by screws, and after removing the screws the plate may be lifted of, the central section, u, removed, the end pieces, t t, slid diagonally inward, so that the projecting portions thereof are withdrawn from the grooves in the formed frame, after which the entire center may be removed.

My improved plate-holder is entirely lighttight, being made without any points whatever,

except where the slide enters the frame.

Springs may be attached to the vseptum C to hold the plates in position in the grooves r1' r t".

The fra-me A maybe molded in a die or mold of suitable form without the septum C, the latter being made of any suitable material and introduced into the frame after it has been formed. y

Provision may be made for the escape of any excess of plastic material during the molding operation through openings or holes made through the walls of the mold.

The frame of my plateholder may be made in halves without the septum, the division being upon a line drawn longitudinally through the center of the frame, as shown in Fig. 13,

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the two halves being fastened together after molding in any preferred way,.thus obviating the necessity of the collapsible center or mold; or my improved plate-holder may be made in the usual way, in halves, secured together by hinges or clasps, in which case the septum is introduced separately, and each half-trame is provided with a recess for the light-excluding shutter.

My invention is restricted to that class of devices which are employed for the purpose of holding sensitized dry plates and excluding the same from the light. It has no relation to those devices which are employed for holding wet plates whilepreparin g or washin gthe same, nor to those holders which are employed for holding plates while being drained.

I am aware thata wooden frame for holding wet plates has been provided with inserted glass corners. I am also aware that an open frame or rack has been cast in one piece of vitreous fragile material. To such devices I lay no claim.

The presentinvention is limited to those matters and things which are specifically claimed herein, and the right is reserved to make any and all features which may be shown but not claimed the subject of future application.

I claim- I. As a new article of manufacture, the dryplate holder or dark frame for photographic purposes having its body formed from plastic material in one continuous piece.

2. As a new article ot' manufacture, the seamless dry-plate holder or dark frame constructed of plastic material withoutjoints or seams, substantially as shown and described.

3. As a new article ot" manufacture, a dryplate holder consisting of an external frame cast in one continuous piece, having a plate or shutter inserted through an opening in one end and seated in grooves in its interior edges.

4. In combination with a plate-holder for photographic cameras, the shutter-recess F, bored or molded from one side of the frame and closed by a cap, D, substantially as described.

WILLIAM HALL WALKER.

Witnesses:

H. G. PHILLIPS, Jos. LACROIX. 

